| Summary table |
|---|
| Variable |
Value |
Source |
| GRB_name_Fermi |
GRB220825082 |
|
| T0 |
1:57:41.847 UTC |
Fermi_GBM |
| ra |
87.9000° |
Fermi_GBM |
| decl |
-10.7800° |
Fermi_GBM |
| pos_error |
6.16e+00° |
Fermi_GBM |
| T90 |
14.08 s |
Fermi_GBM |
| T90_error |
1.086 s |
Fermi_GBM |
| T90_start |
1:57:41.847 UTC |
Fermi_GBM |
| fluence |
2.43e-06 erg/cm² |
Fermi_GBM |
| fluence_error |
4.17e-08 erg/cm² |
Fermi_GBM |
| T100 |
14.08 s |
|
| GBM_located |
True |
|
| mjd |
59816.08173434028 |
Fermi_GBM |
| Fermi GBM table |
|---|
| GRB_name_Fermi |
GRB220825082 |
| trigger_name |
bn220825082 |
| ra |
87.9000° |
| decl |
-10.7800° |
| pos_error |
6.16e+00° |
| datum |
2022-08-25 |
| t_trigger |
1:57:48.503 UTC |
| T90 |
14.08 s |
| T90_error |
1.086 s |
| T90_start |
1:57:41.847 UTC |
| fluence |
2.43e-06 erg/cm² |
| fluence_error |
4.17e-08 erg/cm² |
| flux_1024 |
4.96e+00 erg/cm²/s |
| flux_1024_error |
3.70e-01 erg/cm²/s |
| flux_1024_time |
-1.98e+00 erg/cm²/s |
| flux_64 |
8.85e+00 erg/cm²/s |
| flux_64_error |
2.01e+00 erg/cm²/s |
| GCN 32482 table |
|---|
| GRB_name |
GRB220825A |
| GCN_number |
32482 |
| Detection_method |
Fermi GBM Other |
| ra |
87.9000° |
| decl |
-10.8000° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 32482
SUBJECT: GRB 220825A: Fermi GBM Final Localization
DATE: 22/08/25 16:46:46 GMT
FROM: Joshua Wood at MSFC/Fermi-GBM
The Fermi GBM team reports the detection of a likely LONG GRB
At 01:57:48.50 UT on 25 Aug 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220825A (trigger 683085473 / 220825082).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 87.9, Dec = -10.8 (J2000 degrees, equivalent to J2000 05h 52m, -10d 48'), with a statistical uncertainty of 5.7 degrees.
The angle from the Fermi LAT boresight is 115.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220825082/quicklook/glg_skymap_all_bn220825082.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220825082/quicklook/glg_healpix_all_bn220825082.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220825082/quicklook/glg_lc_medres34_bn220825082.gif
|
| GCN 32483 table |
|---|
| GRB_name |
GRB220825A |
| GCN_number |
32483 |
| Detection_method |
Swift Other |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 32483
SUBJECT: GRB 220825A: Swift/BAT-GUANO detection
DATE: 22/08/26 04:07:21 GMT
FROM: Aaron Tohuvavohu at U Toronto
James DeLaunay (UAlabama), Aaron Tohuvavohu (U Toronto), Gayathri
Raman (PSU), Jamie A. Kennea (PSU), report:
Swift/BAT did not localize GRB 220825A onboard (T0: 2022-08-25T01:57:48
UTC, Fermi/GBM trig #683085473).
The Fermi notice, distributed in near real-time, triggered the Swift
Mission Operations Center operated Gamma-ray Urgent Archiver for Novel
Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1).
Upon trigger, GUANO sent a command to the Swift Burst Alert Telescope
(BAT) to save 200 seconds of BAT event-mode data from [-45,+45]
seconds around the time of the burst. All the requested event mode
data was delivered to the ground.
The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu,
arXiv:2111.01769), detects the burst with a sqrt(TS) of 9.1 in a
16.384 s analysis time bin.
NITRATES results, independently, are ambiguous with respect to whether
this burst originates from in or outside the BAT FOV, with a
borderline DeltaLLHOut of 7.7 and no specific location in the FOV
significantly preferred.
Independent spectral and/or fluence measurements of this burst from
other instruments could help determine the preferred spatial origin.
See Section 9.1 and Figure 20 in the NITRATES paper for brief
descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and
DeltaLLHOut.
GUANO is a fully autonomous, extremely low latency, spacecraft
commanding pipeline designed for targeted recovery of BAT event mode
data around the times of compelling astrophysical events to enable
more sensitive GRB searches.
A live reporting of Swift/BAT event data recovered by GUANO can be
found at: https://www.swift.psu.edu/guano/
|
| GCN 32490 table |
|---|
| GRB_name |
GRB220825A |
| GCN_number |
32490 |
| Detection_method |
Fermi GBM Det |
| t_trigger |
1:57:48.500 UTC |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 32490
SUBJECT: GRB 220825A: Fermi GBM observation
DATE: 22/08/26 20:30:29 GMT
FROM: Sarah Dalessi at UAH
S. Dalessi (UAH), C. Fletcher (USRA), C. Meegan (UAH), and J. Wood (NASA MFSC)
report on behalf of the Fermi GBM Team:
"At 01:57:48.50 UT on 25 August 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220825A (trigger 683085473 / 220825082),
which was also detected by the Swift/BAT-GUANO (J. DeLaunay et al.
2022, GCN 32483).
The angle from the Fermi LAT boresight at the GBM trigger time is 115.0 degrees.
The GBM light curve consists of a single peak burst
with a duration (T90) of about 14.1 s (50-300 keV).
The time-averaged spectrum from T0-4.1 s to T0+8.2 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.24 +/- 0.19 and
the cutoff energy, parameterized as Epeak, is 56.6 +/- 7.0 keV
The event fluence (10-1000 keV) in this time interval is
(1.83 +/- 0.14)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-1.98 s in the 10-1000 keV band
is 4.96 +/- 0.37 ph/s/cm^2.
A Band function fits the spectrum equally well
with Epeak= 46.2 +/- 9.5 keV, alpha = -0.96 +/- 0.37 and beta = -2.48 +/- 0.32.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html
For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"
|